张伟杰（梁朝伟）在警界服务多年，屡建奇功，因此获调派往严重罪案调查科。杰办案时认识了退隐江湖的车房老板边城（高雄），两人惺惺相惜，成为知己。惟城逼于情势而重投黑社会，与杰为敌。 另方面，杰的婚姻亦起风波，妻子叶巧宜（曾华倩）提出离婚，而清新可人的酒廊歌手程月如（邓萃雯）此时闯进杰的生命中…… 时两大黑社会巨头郑康贵（光毅）、卓寿贤（鲍方）展开恶斗，杰受命铲除两帮势力，却因而连累了宜…… 一连串冲击接踵而来，杰将如何面对？
许佳佳继承父志，加入社会安全支队，和队员们一起维护社会治安。
When Joni was 14, her best friend Gracie Darling disappeared during a séance. Some 27 years on, the local kids in a small town get their kicks with a game of ‘Playing Gracie Darling’ – but the seemingly innocent game turns sinister when another girl disappears. Joni, by then a child psychologist, returns to the town and partners with a police sergeant Jay to uncover the truth, while Gracie’s sister Ruth faces a mother’s worst nightmare when her own daughter vanishes under hauntingly similar circumstances.
